Table 1.
Evidence Statements
| Statement or recommendation | Grade |
|---|---|
| Hepatic steatosis | |
| Exercise is effective for reducing hepatic steatosis by modest amounts (2–4% absolute reductions). High certainty of evidence | A |
| Aerobic exercise of at least moderate-intensity results in moderate absolute reductions in hepatic steatosis of ~ 2–4% in adults with MAFLD. High certainty of evidence | A |
| The benefit of aerobic exercise on reduction in hepatic steatosis may extend to children and adolescents, but because there are fewer studies the certainty of evidence for this is low | C |
| The efficacy for resistance training on reducing hepatic steatosis is uncertain. There is some evidence that resistance training may reduce hepatic steatosis by a modest amount; however, evidence is mixed possibly because there is significant variability in study methodologies including the resistance training prescription. Low certainty of evidence | C |
| There is limited evidence for the effect of combined (same session) aerobic and resistance training on hepatic steatosis. No recommendations due to insufficient evidence | Consensus-based recommendation |
| Emerging evidence suggests that HIIT may be comparable to moderate intensity continuous training for reducing hepatic steatosis; however there is insufficient evidence to make firm recommendations for HIIT. Moderate certainty of evidence | B |
| There is limited evidence for the effect of SIT or other novel training approaches (e.g. acceleration training, Pilates) on hepatic steatosis. No recommendations due to insufficient evidence | Consensus based recommendation |
| Liver histology – fibrosis, inflammation, hepatocyte ballooning, NAFLD activity score | |
| There is minimal evidence for the effect of exercise on histological features of MAFLD or liver disease severity beyond the established benefits of exercise on hepatic steatosis and on general health and wellbeing. No recommendations due to insufficient evidence | D |
| Liver enzymes | |
| Aerobic exercise appears effective for improving ALT by a small (6–7 IU/L) amount. Low certainty of evidence | C |
| The efficacy of resistance training for improving liver enzymes is unclear. No recommendations due to insufficient evidence | D |
| There is minimal evidence for the effect of HIIT for improving ALT. No recommendations due to insufficient evidence | D |
| There is limited evidence for the effect of combined exercise training, SIT or other novel training approaches on liver enzymes. No recommendations due to insufficient evidence | Consensus based recommendation |
| Anthropometrics | |
| Exercise reduces BMI by a small amount (~ 0.8 kg/m2). High certainty of evidence | A |
| Exercise appears to reduce waist circumference by a modest (~ 1.2 cm) amount. Low to moderate certainty of evidence | C |
| Aerobic exercise is effective for improving BMI by a small (~ 0.85–0.97 kg/m2) amount. High certainty of evidence | A |
| There is limited evidence for the effect of combined exercise training, resistance training, HIIT, SIT or other novel training approaches on body weight or waist circumference. No recommendations due to insufficient evidence | Consensus based recommendation |
| Aerobic exercise may improve VAT in people with MAFLD; however, evidence in populations with MAFLD is lacking. Low certainty of evidence | D |
| Comorbidities | |
| Aerobic exercise improves cardiorespiratory fitness by a clinically meaningful (~ 3.5–8.0 ml/kg/min) amount in people with MAFLD. High certainty of evidence | A |
| Exercise appears to improve total cholesterol and LDL-cholesterol in people with MAFLD. Moderate certainty of evidence | B |
| There is minimal evidence for the effect of exercise on other cardiometabolic risk factors or comorbidities associated with MAFLD including glycaemic control, vascular health and health-related quality of life. No recommendations due to insufficient evidence | D |
Grade category description: Evidence-based recommendations (A-D): A, body of evidence can be trusted to guide practice; B, body of evidence can be trusted to guide practice in most situations; C, body of evidence provides some support for recommendation, but care should be taken in its application; D, the body of evidence is weak and the recommendation must be applied with caution. Consensus-based recommendation, recommendation based on clinical opinion and expertise as insufficient evidence is available. MAFLD metabolic-associated fatty liver disease, HIIT high-intensity interval training, SIT sprint interval training, ALT alanine aminotransferase, AST aspartate aminotransferase, BMI body mass index, LDL low-density lipoprotein, VAT visceral adipose tissue